Bellow Stem Seals Fractional Flow Control Valves

Bellows stem seals eliminate fugitive emissions by surrounding the valve stem with a pressure-tight barrier, isolating the stem from the process fluid and preventing leakage to the atmosphere. For an extra measure of protection, the bellows stem seal option provides a back-up seal of Teflon or Graphite/Grafoil packing along with a threaded or NPT detection port for use in monitoring potential emissions leakage.

  • Pilot plant installations
  • Test stands
  • R & D facilities
  • Processing plants
  • Fugitive emissions
  • Hazardous service


  • Aviation & aerospace
  • Chemical, refining & petrochemical
  • Oil & gas
  • Process or industrial
  • Test Equipment & Services
Features & Benefits
  • Rolling diaphragm
  • Standard bonnet port for use in lubricating the packing for added protection against leakage or for use as a detection port for monitoring potential fugitive emissions
  • Tri-ply bellows provides added strength and enhanced performance
  • Interchangeable trim sets
  • Threaded bonnet for easy removal of the bellows assembly
  • Bolted body/bonnet connection
  • Optional side mounted or top mounted positioner

Size Type: Globe – Class IV or VI

Sizes: 1/4″ – 3/4″ (DN8 – DN20)

End Connections: Threaded, Socket Weld, Integral Tube, Welded Flange

Body Materials: Carbon Steel, Stainless Steel, Hastelloy C, Monel, Alloy 20, others

Cv (Kv): 0.00001 to 4.0 (0,000009 to 3,4)

Ranges: 3-15 or 6-30 psi; split ranges are available with optional positioner


Installation and Maintenance Videos

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Product Overview Videos

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CRN Number
ATEX Certified

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